Topic 1 - classification 0.0 / 5 ? BiologyclassificationASNone Created by: AliceBrown22Created on: 04-12-17 19:01 Hierarchical classification system 7 levels of taxonomic structure which are based on characteristics (morphology, embryology, biochemical analysis (protien analysis, DNA analysis)): Kingdom - Animalia, Plantae, Fungi, Protoctista, prokaryote. phylum - a large grouping of all the classes that share some common features. class - a grouping of similar orders. order - a grouping of related families. family - a grouping of similar genera. genus - a group of species that are very closely related. species- a group of organisms that can successfully interbreed to produce a fertile offspring. 1 of 10 The five kingdoms - Prokaryotae Bacteria have prokaryotic cells. The cells have no distinct nucleus. Don't have membrane-bound organelles. 2 of 10 The five kingdoms - Protoctista A collection of eukaryotic organisms including algae - photosynthetic but not plants. The Protoctista seems to be the group in which organisms end up if they are not fungi, plants or animals. Many have eukaryotic cell features such as chloroplasts. 3 of 10 The five kingdoms - Fungi Fungi are not able to photosynthesize. Their cell walls are made of a polysaccharide called chitin. Their bodies are composed of masses of filaments called hyphae which are not divided up into separate cells. most are saprobiont, obtaining their food by the extracellular digestion of dead organic material. Fungi have membrane-bound organelles. 4 of 10 The five kingdoms - Plants Plants are multicellular. They have chlorophyll and are photosynthetic. Their cells have a cellulose cell wall and sap-filled vacuole. Many have proper stems, roots and leaves. Primitive plants reproduce by spores; more advanced forms, such a flowering plants, produce seeds. 5 of 10 The five kingdoms - Animals Animals are multicellular. They are heterotrophic - they are unable to make their own food and need a supply of organic food material. They have nervous systems and are able to move about. Growth occurs throughout the body. 6 of 10 Phylogenetic classification system Based on evolutionary history. all species evolve from one common ancestor. LUCA - last universal common ancestor. Analogous structures: different structures but same function - arise due to convergent evolution. Homologous structures: same structures different functions - an example of adaptive radiation. Pentadactyl limb: an example of a homologous structure. five fingered/toed limb. shared with mammals, reptiles, amphibians, and birds but not fish. All organisms have DNA with 1 of 4 bases - this is the main piece of evidence for LUCA because he has all 4. 7 of 10 Three domain classification system This is a way of classifying organisms based on differences in ribosomal RNA structure. Classified into 3 domains and 6 kingdoms. Domains: archaea bacteria eukarya Kingdoms: Archaebacteria Eubacteria Protista Fungi Plantae Animalia 8 of 10 Natural selection Overproduction in offspring but no increase in population - shows a struggle to survive. Variations occur in offspring. Due to competition and struggle to survive only the offsprings with beneficial variations in characteristics survive. The offsprings that survive can go on to reproduce and pass on their beneficial characteristics to future generations of the species. Over time the number of individuals with the beneficial characteristic increases. 9 of 10 Mass extinction Extinction: permanent loss of a species. Mass extinction event: an event that causes the majority of species to go extinct. Evolutionary bottleneck: the small amount of species that survive a mass extinction event. 10 of 10
Genetic information, variation and relationships between organisms AQA AS Biology PART 4 of 6 TOPICS: Species and Taxonomy 5.0 / 5 based on 1 rating Teacher recommended
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